SOUND ON SOUND

[BJG145]

I've recently been experimenting with putting together a DIY MIDI instrument. I've got this idea for a system where different 'dumb' controllers could be plumbed into the same Arduino-based brain, but I'm a bit stuck with deciding on a standard, compact, cheap, multi-pin cable with connector to link them up. At the moment I'm running Cat 5 network cable from the controller with an RJ45 breakout on the processor, but that only has 8 wires; I could do with more like 15 really. Any suggestions...?

[James Perrett]

A D type connector would be the obvious choice - plenty of VGA cables using 15 pin D connectors.

[BJG145]

Thanks James, yeah, that's probably the most realistic option. I was hoping for something a bit more compact, and I just came across 24-pin USB-C, but I'm thinking I might find the wires impossibly thin to work with. (Alternatively it sounds like I should be reading up on multiplexer ICs to get multiple buttons down to fewer wires.)

[zenguitar]

My Arduino/Raspberry Pi experiments have been on the back burner for a few years but I do recall all sorts of breakout boards being available for all sorts of connectors. So I Googled and Lo!

How about a USB-C breakout board?

http://www.saikosystems.com/web/p-86-us ... d-v20.aspx

Would that do the job for you?

Andy :beamup:

[Sam Inglis]

What about Lemo connectors?

[ef37a]

HDMI? Reliable, ubiquitous (you can buy V cheap leads from RockBottom and butcher them) and versatile, you can buy inline couplers (Homebase by crickey!) angled adaptors etc.

In case you are worried that they are non-standard for other than video? My ESI 1010E uses an HDMI cable* from the PCIe card to breakout box.

*ESI maintain the umbilical is NOT a standard HDMI cable but I bought a 5mtr one from Morrisons on offer years ago. Works famously!

Dave.

[BJG145]

Great, thanks for all the ideas!

[Folderol]

Another way you can do this if you fancy some real DIY and a bit of logic work is to use the matrix controller out of an old PS2 type keyboard, that will give you up to 105 buttons and three LEDS down a 6 pin cable - although only 4 are needed.

An arduino can be persuaded to send (near enough) the correct serial rate, or you could build it with CMOS 4000 series demultiplexers and a simple clock

[ef37a]

Another way you can do this if you fancy some real DIY and a bit of logic work is to use the matrix controller out of an old PS2 type keyboard, that will give you up to 105 buttons and three LEDS down a 6 pin cable - although only 4 are needed.

An arduino can be persuaded to send (near enough) the correct serial rate, or you could build it with CMOS 4000 series demultiplexers and a simple clock

That's easy for you to say...!

Dave.

[BJG145]

For a cheap and cheerful hardware solution, micro-HDMI or USB-C with 19 and 24 pins respectively look ideal. I'm a bit puzzled by the reversible nature of USB-C though...is that somehow implemented in "hardware", so that it would work with a simple button-to-input connection, or does it stem more from the protocols or something...? It's neat if it's physical.